<p>Micron&#39;s offices in Folsom, Calif. The memory chipmaker has started a search for a new C.E.O. after Mark Durcan, who held the position since 2012, announced plans to retire. (Image courtesy of Micron).</p>

Mark Durcan, the chief executive of Micron Technology, is planning to retire. The memory chip maker said Thursday that Durcan would stay in his position until a replacement is found.

After serving as Micron’s chief operating officer for five years, Durcan was promoted to chief executive in 2012. He postponed his retirement to take over for Steven Appleton, the company's long-time chief executive, who died in an airplane crash in Boise.

Durcan, 55, joined the Boise, Idaho-based firm as a process integration engineer in 1984, climbing the ranks to chief technology officer and later president.

“Mark Durcan recently discussed with the Board his desire to retire from Micron when the time and conditions were right for the company," said Robert E. Switz, Micron’s chairman, in a statement.

As chief executive, Durcan steered the memory chip business through choppy financial waters that only recently calmed down. In 2015, he weathered the controversy around a Chinese chip maker's $23 billion offer for the weakened company. Last year, Micron's doldrums reached such lows that the company said that it would cut around 2,400 jobs or 7.5% of its workforce.

There have also been changes to Micron's products and how the company develops them. Durcan oversaw Micron’s push into three-dimensional memory chips and new markets like automobiles and industrial equipment. He also expanded an Intel partnership that resulted in 3D XPoint, a memory technology that Durcan has said will combine aspects of both DRAM and NAND.

When he accepted the job in 2012, Durcan appeared to be something of a placeholder before another Micron executive took the reins. He had planned to retire and the company had been said for years to be grooming Mark Adams, then the vice president of worldwide sales, for the chief executive role.

But Durcan stayed in the position, which for several years made him the highest paid chief executive in Idaho. Adams resigned from Micron in early 2016 for what the company said were “personal health reasons.” He has since become the chief executive of Lumileds, a manufacturer of light-emitting diodes.

In recent years, the semiconductor industry's top echelons have been in flux. T.J. Rodgers, the salt-tongued founder and chief executive of Cypress Semiconductor, stepped down last August after 34 years. In 2015, Intel recruited former Qualcomm executive Venkata “Murthy” Renduchintala to oversee most of its product development.

It is not clear whether Micron will recruit from within its ranks for Durcan's replacement. But the company said that Durcan would be part of the search team.